1. Field of the Invention
The invention relates to a switch, more particularly to a sensor device that may be used as a switch.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional vibration switch 10, as disclosed in U.S. Pat. No. 6,740,867, includes an insulated casing 11, an emitter 12 and a receiver 13 disposed in the insulated casing 11 and spaced apart from each other, a seal member 14 disposed in the insulated casing 11, a conductive ball member 15 disposed rollably in the seal member 14, and an insulated cover 16 covering the insulated casing 11. The insulated casing 11 has a central concavity 111, two side concavities 112, 113 located respectively on two opposite sides of the central concavity 111, an emitter slit 114 communicating with the central concavity 111 and the side concavity 112, and a receiver slit 115 communicating with the central concavity 111 and the side concavity 113.
The emitter 12 is retained in the side concavity 112, and has a light emitting point 121 located in the emitter slit 114 to emit light, and a pair of contact terminals 122 extending downwardly and outwardly of the insulated casing 11. The receiver 13 is retained in the side concavity 113, and has a light receiving point 131 located in the receiver slit 115 to receive the light emitted by the emitter 12, and two contact terminals 132 extending downwardly and outwardly of the insulated casing 11.
The seal member 14 is disposed in the central concavity 111, and has two sealing parts 141, 142 fitted to each other, a ball chamber 143 confined cooperatively by the sealing parts 141, 142, and two openings 144, 145 formed respectively in the sealing parts 141, 142. The conductive ball member 15 is configured as a transparent ball, and is disposed in the ball chamber 143 between the light emitting point 121 and the light receiving point 131.
In use, the emitter 12 emits light through the light emitting point 121. The light passes through the opening 144 in the sealing part 141 towards the conductive ball member 15. The light is refracted as it passes through the conductive ball member 15 so that some of the light rays that pass through the opening 145 are received by the light receiving point 131 of the receiver 13. When the light receiving point 131 receives a stable light signal, the vibration switch 10 may be set to a first state, for example, an ON state. When the vibration switch 10 is acted upon by an external force, the conductive ball member 15 is rolled in the ball chamber 143 so as to change the amount of refraction of the light. As such, the light receiving point 131 receives light signals of varying intensity. When this occurs, the vibration switch 10 may be set to a second state, for example, an OFF state.
Although the aforementioned vibration switch 10 can achieve its intended purpose, it has many components, its assembly is time-consuming, and it has a large volume.